Re: [PATCH v2 00/10] drm/panel: Use refcounted allocation for remaining panel drivers

[Thomas Zimmermann <tzimmermann@suse.de>]

For this series:

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>

Am 08.05.26 um 09:04 schrieb Albert Esteve:
> This series converts 9 remaining panel drivers from the deprecated
> devm_kzalloc() + drm_panel_init() pattern to the refcounted
> devm_drm_panel_alloc() API. This follows the work by Anusha Srivatsa
> who introduced the refcounted panel allocation infrastructure [1] and
> converted a first batch of drivers [2] (the last part of a 5 sub-series).
>
> Reasoning:
> ----------
> The old allocation pattern is unsafe: when the panel device is
> unbound, devm frees the context struct immediately, but the DRM
> device may still hold a reference to the embedded drm_panel through
> the panel bridge, leading to a use-after-free. devm_drm_panel_alloc()
> wraps the allocation in a kref scheme, so the memory is only freed
> when the last reference is dropped.
>
> After this series, there are no remaining callers of drm_panel_init()
> under drivers/gpu/drm/panel/, and drm_panel_init() is entirely removed
> from the public API.
>
> [1] https://lore.kernel.org/all/20250331-b4-panel-refcounting-v4-0-dad50c60c6c9@redhat.com/
> [2] https://lore.kernel.org/all/20250710-b4-driver-convert-last-part-july-v1-0-de73ba81b2f5@redhat.com/
>
> Signed-off-by: Albert Esteve <aesteve@redhat.com>
> ---
> Changes in v2:
> - Remove drm_panel_init/alloc precedence mentions in kdocs
> - Link to v1: https://lore.kernel.org/r/20260507-drm_panel_init_rm-v1-0-51f448c7c291@redhat.com
>
> ---
> Albert Esteve (10):
>        drm/panel/visionox-g2647fb105: Use refcounted allocation in place of devm_kzalloc()
>        drm/panel/samsung-s6e63m0: Use refcounted allocation in place of devm_kzalloc()
>        drm/panel/novatek-nt37700f: Use refcounted allocation in place of devm_kzalloc()
>        drm/panel/lxd-m9189a: Use refcounted allocation in place of devm_kzalloc()
>        drm/panel/ilitek-ili9806e: Use refcounted allocation in place of devm_kzalloc()
>        drm/panel/tdo-tl070wsh30: Use refcounted allocation in place of devm_kzalloc()
>        drm/panel/sharp-ls043t1le01: Use refcounted allocation in place of devm_kzalloc()
>        drm/panel/truly-nt35597: Use refcounted allocation in place of devm_kzalloc()
>        drm/panel/startek-kd070fhfid015: Use refcounted allocation in place of devm_kzalloc()
>        drm/panel: Make drm_panel_init() static
>
>   drivers/gpu/drm/display/drm_dp_helper.c             |  2 --
>   drivers/gpu/drm/drm_panel.c                         |  7 +++----
>   drivers/gpu/drm/panel/panel-ilitek-ili9806e-core.c  | 10 +++++-----
>   drivers/gpu/drm/panel/panel-lxd-m9189a.c            | 11 ++++++-----
>   drivers/gpu/drm/panel/panel-novatek-nt37700f.c      | 11 ++++++-----
>   drivers/gpu/drm/panel/panel-samsung-s6e63m0.c       | 14 +++++++-------
>   drivers/gpu/drm/panel/panel-sharp-ls043t1le01.c     | 11 ++++++-----
>   drivers/gpu/drm/panel/panel-startek-kd070fhfid015.c | 12 ++++++------
>   drivers/gpu/drm/panel/panel-tdo-tl070wsh30.c        | 14 +++++++-------
>   drivers/gpu/drm/panel/panel-truly-nt35597.c         | 10 +++++-----
>   drivers/gpu/drm/panel/panel-visionox-g2647fb105.c   | 13 ++++++-------
>   include/drm/drm_panel.h                             |  4 ----
>   12 files changed, 57 insertions(+), 62 deletions(-)
> ---
> base-commit: 74fe02ce122a6103f207d29fafc8b3a53de6abaf
> change-id: 20260506-drm_panel_init_rm-3a4489701f10
>
> Best regards,

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)